A two-dimensional radiation display device is a device which displays intensity by color or luminance with a two-dimensional arrangement of the direction of a radiation source. The direction of the radiation source is displayed on a visible image imaged by a CCD (Charge Coupled Device) image sensor or the like in a superimposed manner, thereby intuitively recognizing the direction and the intensity of the radiation source.
As a method which is used to obtain two-dimensional radiation intensity distribution data, a method in which radiation detectors are arranged in a two-dimensional array and the outputs (pulse count values, current values, voltage values, or the like) of the respective radiation detectors are arranged in a two-dimensional arrangement, a method in which a scintillator emitting light with the incidence of radiation is imaged by a CCD camera or the like, or the like is known.
A γ-ray radioactivity distribution imaging method is shown which detects the intensity of γ-rays multiple times to image a radioactivity distribution while rotating a γ-ray detector array with the incidence direction of the γ-rays as a rotation axis. According to this method, a radioactivity distribution in which a predetermined formula is minimal and the relative value of sensitivity of the γ-ray detectors are obtained by fitting calculation using a least squares method, fitting calculation of the predetermined formula is repeatedly performed, and the radioactivity distribution of a radioactive material is obtained.
A γ-ray imaging device which is carried and installed at a site during construction of a nuclear facility, can detect a radiation operation environment, and is designed for the purpose of high sensitivity and compactness, and in which a CdTe semiconductor sensor array having high stopping power and a large single-hole collimator are combined, or the like is disclosed.